EXCHANGE 


THE  OXIDATION  OF  ISOPROPYL  ALCOHOL, 
ACETONE,  AND  BUTYL  COMPOUND  BY 
NEUTRAL  AND  ALKALINE  POTAS- 
SIUM PERMANGANATE 


•.-„. 


DISSERTATION 


PRESENTED   IN  PARTIAL  FULFILLMENT  OF  THE  REQUIREMENTS  FOR  THE  DEGREE 

OF  DOCTOR  OF  PHILOSOPHY  IN  THE  GRADUATE  SCHOOL 

OF  OHIO  STATE  UNIVERSITY 


By 

LILY  BELL  SEFTON 


Columbus,  Ohio 
1921 


THE  OXIDATION  OF  ISOPROPYL  ALCOHOL, 
ACETONE,  AND  BUTYL  COMPOUND  BY 
NEUTRAL  AND  ALKALINE  POTAS- 
SIUM PERMANGANATE 


DISSERTATION 


PRESENTED   IN  PARTIAL  FULFILLMENT  OF  THE  REQUIREMENTS  FOR  jTHE  DEGREE 

OF  DOCTOR  OF  PHILOSOPHY  IN  THE  GRADUATE  SCHOOL 

OF  OHIO  STATE  UNIVERSITY 


By 

LILY  BELL  SEFTON 


Columbus,  Ohio 
1921 


-'.  t :  -:  ••;.•.••..    .'  ." ,-.  A/    0  D( 

:':;-""---:  •-'•--•• 


OUTLINE 

I.  Introduction. 
II.  Isopropyl  Alcohol. 

1.  History. 

2.  Experimental  Part 

3.  Results. 

4.  Discussion  of  Results 

5.  Summary. 

III.  Acetone 

1.  History. 

2.  Experimental  Part. 

3.  Results. 

4.  Discussion  of  Results. 

5.  Summary. 

IV.  Supplement — Butyl  Compounds 
V.  Acknowledgments. 


THE   OXIDATION   OF  ISOPROPYL   ALCOHOL   AND 

ACETONE  WITH  NEUTRAL  AND  ALKALINE 

POTASSIUM  PERMANGANATE 

LILY  BELL  SSFTON 

The  oxidation  of  organic  compounds  has  occupied  the  attention  of  a 
great  many  investigators  during  the  last  sixty  years.  Practically  all  the 
early  work  was  qualitative  in  character  and  was  conducted  in  open  sys- 
tems so  that  the  oxygen  of  the  air  had  an  opportunity  to  act  in  conjunction 
with,  and  thus  modify  the  results  of,  the  specific  oxidizing  agent  used. 
In  1899,  Castle  and  L/oevenhart1  oxidized  formic  acid  with  alkaline  hy- 
drogen peroxide  solution  at  carefully  controlled  temperatures  and  then 
determined  the  final  products  quantitatively.  Since  that  time  the  tend- 
ency has  been  toward  definite  conditions  and  quantitative  measurements. 

The  work  represented  by  this  thesis  is  a  continuation  of  the  work 
already  done  by  Evans  and  Day2  on  ethyl  alcohol  and  by  Evans  and 
Adkins3  on  acetaldehyde,  glycol  and  related  compounds.  It  is  presented 
in  two  divisions: 

I.  The  oxidation  of  isopropyl  alcohol  by  neutral  and  alkaline  potas- 
sium permanganate.     Four  series  of  experiments  were  conducted — one 
at  25°  C.,  one  at  50°  C.,  one  at  75°  C.,  and  one  at  100°  C.     Since  isopropyl 
alcohol  boils  at  a  temperature  much  below  100°  C.  (B.  P.  82.85°  C.)  the 
results  from  the  experiments  made  at  that  temperature  were  very  irreg- 
ular— too .  irregular  to  permit  of  drawing  conclusions   from   them.     The 
alkalinity  of  the  samples  in  each  series  varied  from  0  to  85.12  grams  of 
KOH  per  1000  cc.  of  solution.     Thirty  grams  of  permanganate  were  used 
in  each  sample  and  the  amount  of  alcohol  solution  necessary  for  reduction 
added  at  a  regular  rate.     All  the    reaction  products    were    determined 
quantitatively. 

II.  The  oxidation  of  acetone.     This  was  done  in  the  same  manner  and 
under  the  same  conditions  as  the  oxidation  of  isopropyl  alcohol.     Since 
the  boiling  point  of  acetone  is  even  lower  than  that  of  isopropyl  alcohol 
(B.  P.  56-57°  C.)  the  results  obtained  from  oxidations  made  at  100°  C., 
were  more  irregular  than  those  from  isopropyl  alcohol  at  the  same  tempera- 
ture so  were  not  used  as  a  basis  for  any  conclusions. 

The  purpose  of  the  work  was  three  fold: 

I.  To  determine  the  relation  of  alkalinity  to  the  character  arid  amounts 
of  the  products  of  oxidation. 

II.  To  determine  the  relation  of  temperature  to  the  character  and 
amounts  of  the  products  of  oxidation. 

1  /.  Am.  Chem.  Soc.,  21,  262    (1899). 

2  Ibid.,  38,  375   (1916). 
zlbid.,  41,  1385   (1919). 


6 

III.  To  ascertain  the  mechanism  of  the  reactions  when  isopropyl  alco- 
hol and  acetone  are  oxidized. 

I.     THE  OXIDATION  OF  ISOPROPYL  ALCOHOL 

1 .  Historical. 

The  amount  of  work  which  has  been  done  on  the  oxidation  of  iso- 
propyl alcohol  is  very  small  when  compared  with  that  which  has  been 
done  on  acetone  and  on  the  normal  alcohols — ethyl  alcohol  and  butyl 
alcohol.  M.  Berthelot1  oxidized  isopropyl  alcohol  with  potassium  chro- 
mate  and  sulfuric  acid,  obtaining  only  acetone,  or,  in  the  case  of  the 
more  concentrated  solutions,  the  acetone  oxidation  products.  In  1887, 
Remsen  and  Emerson2  found  upon  oxidizing  a  series  of  aromatic  com- 
pounds containing  alkyl  side  groups,  that  the  isopropyl  group  was  more  easily 
oxidized  by  acid  oxidizing  agents  than  by  alkaline  oxidizing  agents. 
Hetper3  oxidized  isopropyl  alcohol  and  acetone  with  potassium  perman- 
ganate in  both  acid  (phosphoric)  and  alkaline  solutions.  He  was  unable 
to  get  a  complete  combustion  of  either  of  them  in  alkaline  solution. 

2.  Experimental  Part. 

Materials.  The  isopropyl  alcohol  used  was  obtained  from  the  Eastman 
Company.  Four  tests  were  made  of  its  purity. 

Boiling  point.  The  results  of  this  test  were  very  unsatisfactory.  The 
boiling  point  ranged  from  81°-87°  C.  (B.  P.  from  Olsen,  82.25°  C.). 
For  the  series  of  experiments  at  50  °  C.  a  sample  of  alcohol  boiling  between 
82°-84°  C.  was  used.  Unfortunately  this  exhausted  the  supply  on  hand 
so  that  the  material  used  for  the  25°  C.  and  75°  C.  runs  was  from  a  new 
supply. 

Specific  gravity  determinations.  The  first  sample  had  a  density  of  0.8004, 
the  second  0.7976  (Olsen— 0.7898;  0.7960). 

Test  for  water.  Both  samples  gave  a  blue  tinge  very  quickly  to  dehy- 
drated copper  sulphate. 

Oxidation.      The  first  sample  (used  at  50°  C.)  showed  a  yield  of  only 
about  93  per  cent;    the  second  sample   (used  at  25°  and  75°  C.)  gave 
yields   of  from  82-87%.     Isopropyl   alcohol  is   known  to  be  very  hard 
to  free   from  water.4     It   forms  various  hydrates  readily.     The  formula 
C3H8O.XH2O  represents  86.82  per  cent  of  the  anhydrous  alcohol.   The  possi- 
ble hydrate  2C3HgO.^H2O  represents  93.03  per  cent.      Since  the  recovery 
yield  of  the  first  sample  when  oxidized  was  so  consistently  93  per  cent  and 
that  of  the  second  sample  87  per  cent  the  results  obtained  were  calculated 
*Am.  Chem.  Jour.,  23,  212  (1872). 
zlbid.t  8,  262  (1887). 

3  Jour.  fur.  anal.    Chem.,   50,    355    (1911);  51,  417  (1912). 

4  Brlenmeyer  Annalen,  126,  307;  Linneman  Annalen,  136,  40. 


on  the  assumption  that  the  two  lots  of  isopropyl  alcohol  were  hydrates 
of  the  formulas  to  which  their  oxidation  percentage  yields  correspond. 

A  3  N  solution  of  the  alcohol  was  made  up  with  CO2-free  water.  At- 
tempts to  make  a  more  dilute  solution  resulted  in  the  formation  of  a  white 
cloudy  material.  This  milky — apparently  colloidal — substance  concen- 
trated on  top  of  the  mixture.  No  explanation  could  be  found  in  literature 
concerning  such  a  formation.  Whether  it  was  due  to  some  slight  impurity 
in  the  alcohol  or  whether  to  the  formation  of  a  hydrate  less  soluble  than 
the  alcohol  itself  is  supposed  to  be,  is  not  known. 

Potassium  permanganate.  Braun's  product,  99.75  per  cent  pure,  was 
used. 

Water.  Since  the  ordinary  distilled  water  of  the  laboratory  showed 
a  faintly  acid  reaction  (3  drops  of  KOH  were  required  to  produce  a 
pink  color  with  phenolphthalein  in  100  cc.),  carbon-dioxide-free  water 
was  used  in  making  up  every  sample  and  solution  used. 

Potassium  hydroxide  solutions.  Baker's  brand,  purified  from  alcohol, 
was  used. 

A  4.5  N  solution  was  used  for  making  the  samples  alkaline.  The 
carbon  dioxide  content  of  this  solution  was  determined  from  time  to  time. 
(0.0011-0.0012  g.  carbon  dioxide  per  cc.) 

A  j|  solution  was  used  for  determining  the  acetic  acid  content. 

Potassium   permanganate    solution. 

A  ^  solution  was  used  for  determining  the  oxalic  acid. 

Phosphoric  acid.  An  85  per  cent  solution  was  used  in  the  distil- 
lation of  acetic  acid. 

Methods — Oxidation.  Thirty  grams  of  potassium  permanganate  (the 
equivalent  of )  were  weighed  out  and  placed  in  a  wide-mouthed  2-liter  flask. 
To  this  exactly  one  liter  of  the  potassium  hydroxide  solution  was  added. 
The  initial  alkalinity  of  the  solutions  varied  from  0.00  to  85.12  grams  of 
the  base  per  liter.  The  flasks  were  fitted  immediately  with  a  rubber  stop- 
per provided  with  a  tube  for  the  introduction  of  the  reducing  solution,  a 
mercury  seal  through  which  ran  a  motor-driven  stirrer,  and  a  25  cc.  pipette 
for  drawing  up  and  examining  the  reaction  mixture  from  time  to  time.  The 
flasks  were  then  placed  in  the  bath  and  the  delivery  tube  of  each  fitted  to 
the  tip  of  a  burette  containing  the  reducing  solution.  Because  of  the  low 
boiling  point  of  isopropyl  alcohol,  it  was  necessary  to  make  the  connection 
between  the  burette  and  the  delivery-tube  practically  air-tight  lest  iso- 
propyl alcohol  be  lost  by  volatilization.  The  volatility  of  the  isopropyl  alco- 
hol made  it  necessary  also  for  the  end  of  the  delivery  tube  to  be  placed  well 
beneath  the  surface  of  the  solution  in  the  flask.  Preliminary  experiments 
showed  that  the  contents  of  the  flask  came  to  the  temperature  of  the  bath  in 
about  half  an  hour.  In  cases  where  the  temperature  and  the  alkalinity 


8 

were  low,  no  harm  probably  would  have  resulted  from  allowing  the  mixture 
to  stand  for  a  longer  time  but  the  permanganate  in  those  samples  whose 
temperature  and  alkalinity  were  high,  showed  a  tendency  to  decompose 
if  allowed  to  stand  for  some  time  so  care  was  taken  to  make  the  first  ad- 
dition of  alcohol  within  an  hour  at  least,  after  the  permanganate  and 
alkaline  solution  had  been  mixed.  One  cubic  centimeter  of  the  alcohol 
solution  was  added  every  half  hour  until  the  color  of  the  supernatant 
liquid  showed  that  the  end  point  was  near.  Then  the  solution  was  added 
drop  by  drop  and  at  longer  intervals  of  time  until  only  a  faint  pink  color 
could  be  seen.  If  this  pink  color  persisted  over  night  and  could  be  dis- 
charged in  the  morning  by  the  addition  of  two  drops  of  alcohol  solution, 
the  titration  was  considered  successful — if  the  pink  color  disappeared 
over  night,  a  new  sample  was  titrated.  After  the  reaction  was  complete 
the  mixture  was  filtered  in  a  carbon-dioxide  free  atmosphere  by  means  of 
the  apparatus  designed  and  described  by  Evans  and  Day,1  the  precipitate 
washed  three  times  with  cold  water,  and  the  solution  made  up  to  2000  cc. 
with  carbon-dioxide  free  water  and  kept  in  glass-stoppered  bottles  sealed 
with  paraffin.  In  the  case  of  the  neutral  solutions  at  25°  C.  and  50°  C., 
it  was  necessary  to  determine  by  preliminary  experiments  the  approxi- 
mate amount  of  alcohol  needed  and  then  to  start  with  fresh  samples  add- 
ing the  calculated  amount,  one  cubic  centimeter  every  half  hour,  allowing 
whatever  time  was  necessary  for  the  reaction  to  come  to  completion.  The 
necessity  for  the  addition  of  the  alcohol  in  a  regular  manner  will  be  dis- 
cussed later. 

Determination  of  carbon  dioxide.  One  hundred  cc.  of  the  reaction 
mixture  were  used  and  the  estimation  made  by  the  Foulk  method;2  the 
gas  was  absorbed  in  Liebig  tubes  and  proper  corrections  made  for  the  car- 
bon dioxide  content  of  the  potassium  hydroxide  solution. 

Determination  of  oxalic  acid.  One  hundred  cc.  of  the  reaction 
mixture  were  treated  with  an  excess  of  sulfuric  acid  (1:4),  heated  to  80°  C. 
and  titrated  with  standard  potassium  permanganate  solution.  In  order 
to  make  sure  that  no  material  except  the  oxalic  acid  was  being  attacked, 
every  fifth  sample  was  evaluated  by  precipitating  the  oxalic  acid  with 
calcium  acetate,  filtering,  dissolving  the  precipitated  oxalate  and  titrating 
the  solution  with  permanganate.  The  results  obtained  by  the  method 
of  direct  titration  checked  in  every  case  very  closely  with  those  of  the 
precipitation  method. 

Determination  of  acetic  acid.  Two  hundred  cc.  of  the  samples 
were  used  for  these  determinations.  Adkins3  outlined  a  modification  of 
the  Stillwell  and  Gladding  method  for  acetic  acid  and  this  procedure  was 

1  Loc.  cit. 

2  Foulk's  "Notes  on  Quantative  Analysis,"  222. 

3  Loc.  cit. 


followed  with  fair  success.  Control  experiments  showed  a  recovery  of 
99.57  per  cent  of  acetic  acid  but  it  was  found  necessary  with  the  reaction 
solutions  and  especially  with  those  containing  a  higher  percentage  of  acetic 
acid  to  distil  over  more  than  400  cc.  as  recommended  by  Adkins.  The 
method  finally  adopted  was  this :  Four  hundred  cubic  centimeters  of  the 
distillate  were  collected,  the  carbon  dioxide  removed  according  to  the 
method  of  Adkins  and  the  sample  titrated  with  potassium  hydroxide 
solution  using  phenolphthalein  as  an  indicator.  Additional  distillates 
of  from  75-100  cc.  were  collected  and  titrated  until  the  last  distillate  re- 
quired not  more  than  two  drops  of  the  alkaline  solution  to  bring  it  to  end 
point.  Total  volumes  of  from  500-800  cc.  were  collected  before  all  the 
acetic  acid  was  over.  Blank  samples  containing  20  cc.  of  phosphoric 
acid  showed  that  it  was  necessary  to  make  a  correction  of  0.25  cc.  of  the 
hydroxide  solution  for  each  estimation  made. 

Determination  of  acetone.  The  Robineau-Rollins-Kebler  method 
described  later  in  this  paper  was  used  for  the  estimation  of  acetone  in 
most  of  the  samples.  In  those  whose  acetone  content  was  very  low  quali- 
tative tests  were  made  with  salicylaldehyde.  A  small  piece  of  solid  so- 
dium hydroxide  was  placed  in  a  test  tube  with  10  cc.  of  the  test  solution. 
To  this  a  few  drops  of  salicyladehyde  were  added  and  the  mixture  heated 
to  70°  C.  The  appearance  of  a  red  ring  indicates  the  presence  of  acetone. 
This  test  is  very  delicate. 

3.  Results. 

The  results  are  given  in  three  ways — by  (tables,)  by  ordinary  curves  and 
by  logarithmic  curves.  All  experimental  results  were  calculated  to  0.1 
molar  quantity  of  isopropyl  alcohol  and  these  calculated  results  plotted 
against  the  initial  alkalinity  of  the  samples.  The  tables  show  that  30 
grams  of  permanganate  consume  a  much  smaller  quantity  of  isopropyl 
alcohol  than  of  acetone.  The  amount  of  alcohol  oxidized  varies  inversely 
with  the  value  of  the  initial  alkalinity  and  with  the  temperature. 

Acetone  is  found  as  a  reaction-product  in  the  two  lower  series  in  ad- 
dition to  oxalic,  carbonic,  and  acetic  acids.  At  50°  C.  the  amounts  were 
so  small  that  they  could  be  tested  for  only  qualitatively  and  none  was 
found  in  samples  of  an  alkalinity  value  above  2.12  g.  KOH  per  liter.  The 
acetone  production,  then,  like  that  of  acetic  acid  and  carbon  dioxide, 
grows  less  as  the  alkalinity  increases,  and  like  the  acetic  acid  yield,  di- 
minishes with  increasing  temperature.  Josef  Hetper1  explains  "the  im- 
perceptible influence  of  temperature  on  the  oxidation  of  both  isopropyl 
alcohol  and  acetone"  by  saying  that  the  CH3  in  each  is  probably  oxidized 
immediately  by  alkaline  permanganate. 
1  Zeit.  fiir  anal.  Chem.  51,  417  (1912). 


10 


ALCOHOL, 

B  W 

«_,  8         .-£  u       .-xl;  .OS  Sfe  Calculated  yields  from 

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-                    -               -               -  0£  C204     C02    CHsCOOH  CH3COCH3 


Temperature  —25°  C. 

1.  0.00  2.615  1.774  1.864  1.224  0.120  99.29  4.080  4.287  2.815  0.276 

2.  0.50  2.481  2.054  1.793  0.897  0.077  97.92  4.970  4.348  2.178  0.191 

3.  1.06  2.421  2.520  1.705  0.591  0.055  97.93  6.247  4.222  1.465  0.136 

4.  2.12  2.418  2.734  1.696  0.450  0.039  97.45  6.780  4.203  1.116  0.097 

5.  3.18  2.326  2.871  1.628  0.350  0.014  97.77  7.407  4.189  0.903  0.036 

6.  5.32  2.276  2.867   1.595  0.339  Traces  99.12  7.568  4.210   0.895  Traces 

7.  10.64  2.297   2.877    1.612   0.300  Traces  97.75  7.526  4.217   0.784     Traces 

8.  21.28  2.313   2.890    1.600  0.312  Traces  97.12   7.508  4.157  0.810     Traces 

9.  85.12  2.238  2.877    1.588  0.345  Traces  101  .70   7.40     4.262   0.926     Traces 

Temperature  —50°  C. 

1.  0.00  2.423-2.100  1.966  0.740  Traces  96.90   5.202   5.116  1.832     Traces 

2.  0.50  2.360  2.533  1.862  0.421  Traces  96.26   6.438  4.734  1.068    Traces 

3.  1.06  2.345  2.649  1.819  0.386  Traces   97.79   6.774  4.652  0.988     Traces 

4.  2.12  2.308  2.794  1.741  0.322  Traces  98.05  7.263  4.524  0.834     Traces 

5.  3.18  2.289   2.882  1.678  0.289  99.27  7.554  4.398  0.756 

6.  5.32  2.259   2.917  1.634  0.279  100.00  7.746  4.338  0.741 

7.  10.64  2.277   2.965   1.609   0.228  98.01   7.812   4.242  0.600 

8.  21.28  2.260  2.983    1.604  0.230  99.19   7.920  4.254   0.606 

9.  85.12   2.260  2.931    1.593   0.233  97.93   7.795  4.239  0.618 

Temperature  —75°  C. 

1.  0.00   2.224  1.977   2.196  0.271  92.47  5.332  5.920  0.733 

2.  0.50  2.192  2.415    1.932  0.164  95.27  6.610  5.283   0.448 

3.  1.06   2.192  2.620    1.840  0.156  97.29  7.169  5.035  0.414 

4.  2.12   2.177  2.737    1.728  0.149  97.86  7.535  4.750  0.408 

5.  3.18  2.167  2.782   1.658  0.144  97.31  7.680  4.565   0.400 

6.  5.32   2.164  2.832    1.645  0.146  98.69  7.846  4.557   0.400 

7.  10.64   2.164  2.835    1.653   0.143  98.69   7.860  4.579   0.400 

8.  21.28  2.160  2.839    1.630   0.148  98.45  7.873   4.532   0.402 

9.  85.12  2.164   2.838   1.640  0.144  98.53   7.855  4.542   0.400 

Below  is  a  comparison  of  the  results  of  the  oxidation  of  this  iso-alcohol 
with  those  of  ethyl  alcohol1  made  under  practically  the  same  conditions. 

1.  Neutral  permanganate   produces   from   ethyl   alcohol   acetic    acid 
only;  isopropyl  alcohol  produces  oxalic,  carbonic  and  acetic  acids,  and, 
in  samples  oxidized  at  25°  C.  and  50°  C.,  acetone  also.     This  fact  is  a 
very  significant  one  and    will  be  discussed  later. 

2.  Samples  of  low  alkalinity  and  temperature  produce  from  isopropyl 
alcohol  the  four  substances  listed  immediately  above;  under  no  condi- 
tions does  ethyl  alcohol  yield  anything  save  oxalic,  carbonic,  and  acetic 
acids. 

1  Evans  and  Day:  Loc.  cit. 


11 

3.  In  the  case  of  the  ethyl  alcohol  the  maximum  (and    minimum) 
acid  yields  correspond  to  a  point  where  the  alkali  content  of  the  samples 
is  from  90  to  100  grams  KOH  per  liter.     When  the  iso-compound  is  oxi- 
dized, maximum  and  minimum  acid  yields  are  reached  when  the  alka- 
linity is  from  6  to  8  grams  KOH  per  liter. 

4.  An  increase  in  temperature   produces  a  great  deal  more  effect  on 
the  amounts  of  the  products  formed  when  ethyl  alcohol  is  oxidized  than 
when  isopropyl  alcohol  is  oxidized. 

5.  The  rate  of  addition  of  ethyl  alcohol  affects  neither  the  character 
nor  amounts  of  the  products  formed;  in  the  oxidation  of  isopropyl  alcohol 
increased  rate  of  addition  results  in  increased  amounts  of  oxalic  acid. 

4.     Discussion  of  Results. 

There  are  several  possible  ways  in  which  the  oxidation  of  isopropyl 
alcohol  may  take  place. 

1.  CH,  N 

CHOH — >CH3.  CII2OH  -f        CH2 

u          / 

Evans  and  Day  have  shown  that  when  ethyl  alcohol  is  oxidized  under 
conditions  precisely  the  same  as  those  of  this  work,  that  no  oxalic  acid 
is  obtained.  Oxalic  acid  was  one  of  the  end-products  of  the  oxidation 
of  isopropyl  alcohol — it  could  not  have  come  from  the  methylene  radical 
hence  dissociation  possibility  one  is  excluded. 

2.  CH3  OH 

I  / 

CHOH — >CH3.  C-^  +  CH4 

u 

Frequent  tests  made  during  the  oxidation  of  isopropyl  alcohol  showed 
that  no  methane  was  formed.  Evidently  therefore  the  alcohol  does  not 
dissociate  in  the  manner  suggested  above. 

3.  CH3  CH3  CH3 

!  I  I 

CHOH  — >     v     CHOH    — >  CO 

I  \l  I 

CH3  CH  CH2OH 


1  Zeit.  fur  anal.  Chem.,  50,  355. 


12 

Denis1  has  proved  that  acetol  does  not,  when  oxidized  with   perman- 
ganate yield  oxalic  acid.     This  excludes  possibility  three. 

\ 

4.         CH3  CH 

I  /\ 


CHOH  — >  CHOH       +       2H2 

I  \l 

CH3  CH 


Such  a  dissociation  does  not  provide  for  the  formation  of  acetic  acid 
and  cannot  therefore  represent  the  manner  in  which  isopropyl  alcohol 
dissociate  since  acetic  acid  is  one  of  the  end-products  of  the  oxidation  of 
the  isopropyl  alcohol. 

5.        CH3  CH3 

I  I 

CHOH        — >  CO 

I  I 

CH3  CH3 

The  following  facts  are  presented  as  evidence  that  the  reaction  takes 
place  in  the  manner  indicated  by  the  above: 

1.  Berthelot1  found    only    acetone  when  he  oxidized  isopropyl  alcohol 
with  dilute  potassium  dichromate. 

2.  By  the  principle  of  selective  oxidation,  the  secondary  alcohol  group 
would  be  attacked  before  the  very  stable  methyl  groups.2 

3.  The    curves    for    isopropyl  alcohol  follow  very  closely  the  curves 
for  acetone. 

4.  Acetone    in  considerable    quantity    was  found  in  the  samples  of 
isopropyl  alcohol  of  lower  alkalinity  and  temperature. 

5.  Since  any  acetone  formed  during  the  oxidation  of  isopropyl  alcohol 
is  in  the  nascent  condition,  one  would  expect  it  to  be  more  readily  attacked 
than  when  a  solution  of  it  is  added  to  the  permanganate  solution.     This 
is  evidently  the  case:  the  difference  in  the  case  of  oxidation  is  especially 
noticeable  in  samples  of  zero  and  low  alkalinity  at  25°  C.  and  50°  C. 

Further  steps  in  the  oxidation,  that  is,  the  mechanism  of  the  acetone 
itself,  will  be  discussed  in  the  latter  part  of  this  paper. 
5.    Summary. 

1.  Isopropyl  alcohol  yields  oxalic,  carbonic,  and  acetic  acids  at  all 
temperatures  and  degrees  of  alkalinity.  Samples  oxidized  at  25°  C.  and 
50°  C.  with  neutral  permanganate  solution  or  permanganate  solutions 

1  Loc.  cit. 

2  Helper:  Zeit.  anal.  Chem.,  50,  343-70. 


13 

of  low  alkalinity  give  acetone  in  addition  to  the  three  products  named 
above. 

2.  The    amounts    of  acetic  and    carbonic  acids,  and  acetone  formed 
are  inversely  proportional  to  the  degree  of  alkalinity.     The  amounts  of 
oxalic  acid  formed  are  directly  proportional  to  the  alkalinity. 

3.  The   amounts   of  oxalic  and  carbonic  acids  formed  are  directly  pro- 
portional to  the  temperature — the  amounts  of  acetic  acid  and  acetone 
are  inversely  proportional. 

4.  The  logarithms  of  the  amounts  of  oxalic,  carbonic  and  acetic  acids 
are  within  narrow  limits — from  0.5  to  3.18  g.  potassium  hydroxide  per 
liter — linear  functions  of  the  logarithms  of  the  initial  alkali  concentration. 

5.  A    comparison    is  made  of    the  effect  of  neutral  and  alkaline  per- 
manganate on  isopropyl  alcohol  and  ethyl  alcohol. 

6.  The    maximum    (and  minimum)  effects  of   variation  in  initial  alka- 
linity are  reached  when  the  concentration  of  the  alkali  is  from  six  to  eight 
grams  per  liter  of  solution. 


II.    THE  OXIDATION  OF  ACETONE 
1.  History. 

The  history  of  the  oxidation  of  ketones  may,  without  much  exaggera- 
tion, be  said  to  be  the  history  of  the  oxidation  of  organic  compounds,  so 
often  have  they  figured  in  the  work  of  the  various  investigators.  Pean 
de  St.  Gilles1  who  published  one  of  the  first  papers  on  organic  oxidations 
found,  from  the  reaction  of  citric  acid  on  an  acid  solution  of  potassium 
permanganate,  a  compound  which  proved  identical  with  acetone.  Con- 
cerning this  compound  he  made  a  statement  which  has  been  a  matter  of 
dispute  ever  since:  "I  noted,  not  without  surprise  that  it  (the  acetone) 
dissolved  permanganate  without  alteration  even  at  boiling  temperature." 
He  further  said  that  "this  fact  makes  it  possible  not  only  to  establish  the 
purity  of  the  acetone  but  also  to  purify  a  commercial  sample  by  destroy- 
ing any  oxidizable  material  in  it."  A  discussion  of  this  point  will  be  taken 
up  later. 

A.  Popoff2  from  the  results  of  his  own  work  and  that  of  Kolbe,  Wurtz, 
Erlenmeyer,  Wanklyn  and  Butlerow  made  some  valuable  generalizations 
concerning  the  manner  in  which  mixed  ketones  react  when  treated  with 
an  acid  solution  of  potassium  dichromate.  The  two  best-known  of  these 
rules  are  (1),  "When  a  ketone  whose  alcohol  radicles  are  of  the  same  series, 
but  not  isomeric,  is  oxidized,  the  carbonyl  remains  linked  to  the  alcohol 
radical  poorest  in  carbon;"  and  (2)  "When  the  alcohol  radicles  of  a  ketone 

1  Ann.  Chem.  et  Phys.  sec.  3,  55,  396  (1895). 

2  Deut.  Chem.  ges.  Ber.,  4, 720  (1871) ;  Ibid.,  38, 41  (1872) ;  Annalen,  161, 289  (1892). 


14 

belong  to  different  series,  the  aromatic  group  will,  upon  treatment  of  the 
ketone  with  an  oxidizing  agent,  remain  with  the  carbonyl  group  giving 
rise  to  the  corresponding  acid  while  the  aliphatic  group  will  be  further 
oxidized."  Frequent  exceptions  to  these  rules  have  been  found.  Wag- 
ner1 from  ethyl-propyl  ketone  obtained  butyric  and  acetic  acids  with 
propionic  acid  as  the  result  of  a  secondary  reaction  and  Glucksmann2 
working  with  pinacoline  and  alkaline  permanganate  obtained  only  tri- 
methyl  pyruvic  and  tri-methyl  acetic  acids.  Hercz,3  on  the  other  hand, 
in  his  work  on  acetone  confirms  Popoff's  rules  as  do  Buchka  and  Irish4 
who,  from  acetophenone  and  alkaline  potassium  ferricyanide  obtained 
only  benzoic  acid  and  carbon  dioxide.  Later,  Evans5  using  the  same 
materials,  acetophenone  and  alkaline  ferricyanide,  obtained  benzoylformic 
acid  and  benzoic  acid.  It  is  possible  that  in  contradicting  or  confirming 
such  general  statements  as  Popoff's  rules  for  the  oxidation  of  ketones, 
too  little  account  has  been  taken,  up  to  date,  of  the  fact  that  the  differ- 
ences in  the  oxidizing  agents,  in  the  media,  in  the  temperature,  etc.  make 
marked  differences  in  the  character,  as  well  as  in  the  amounts,  of  the  final 
products.  The  work  of  Josef  Hetper6  illustrates  such  differences  ad- 
mirably. He  oxidized  a  large  number  of  organic  bodies,  first  with  acid, 
and  then  with  alkaline,  permanganate  and  found  that  the  results  from  the 
two  series  varied  widely.  (He  used  phosphoric  acid  in  these  experiments.) 
Peter7  used  alkaline  permanganate  to  oxidize  acetothienone,  C^HsSCOCHs 
and  obtained  /3-Thienylglyoxylic  acid  C4H3SCO.COOH  in  addition 
to  thiophenic  acid  C^sSCOOH.  When,  however,  he  tried  to  obtain 
phenylglyoxylic  acid  in  a  similar  manner  from  acetophenone,  he  failed. 
Claus  and  Stronmeyer8  repeated  the  latter  experiment  and  obtained  the 
same  results.  Buchka  and  Irish9  were  able  to  produce  small  amounts  of 
phenylglyoxylic  acid  by  oxidizing  acetophenone  with  alkaline  ferricyanide 
but  they,  prejudiced  evidently,  in  favor  of  Popoff's  rule  sought  to  explain 
this  result  by  postulating  a  secondary  reaction  whereby  benzaldehyde 
produced  from  a  decomposition  of  acetophenone  unites  with  unused  aceto- 
phenone and  hydrocyanic  acid  to  form  a  cyanhydrin  from  which  the  keto- 
'  acid  is  produced.  In  1890,  Glucksmann10  by  treating  acetophenone  with 
alkaline  permanganate  at  a  low  temperature  obtained  a  good  yield  of 

1  Jour,  prakt.  Chem.,  44,  257  (1892). 

2  Monat.  fiir  Chem.,  10,  782  (1889). 

3  Lieb.  Ann.,  186,  257  (1877). 

4  Ber.,  20,  386  (1887). 

5  Am.  Chem.  Jour.,  35,  115  (1906). 

6  Zeit.  anal.  Chem.,  51,  409  (1912). 
•<  Ber.,  18,  537  (1885). 

8  Ibid.,  19,  230  (1886). 

9  Loc.  cit.     See  also  Bvans — Loc.  cit. 

10  Monat.  fur.  Chem.,   11,  246    (1890). 


15 

phenylglyoxylic  acid.  He  attributed  the  failure  of  his  predecessors  to 
the  fact  that  they  did  not  use  an  excess  of  acetophenone.  When  an  excess 
is  used,  the  keto-acid  which  he  regards  as  a  product  of  the  primary  reac- 
tion, is  kept  from  oxidizing  further. 

All  of  this  work  on  acetophenone  has  a  distinct,  if  indirect,  bearing 
upon  the  question  of  the  production  of  pyruvic  acid  from  acetone.  Four- 
nier1  was  the  first  to  present  conclusive  evidence  that  pyruvic  acid  was 
formed  from  acetone  and  alkaline  permanganate  altho  Pastareau2  three 
years  before  had  found  it  in  the  reaction-product  of  acetone  and  alkaline 
hydrogen  peroxide.  Fournier  showed  that  the  yield  of  pyruvic  acid  was 
inversely  proportional  to  the  temperature  and  to  the  length  of  time  re- 
quired for  oxidation,  and  that  above  20°  C.  the  pyruvic  acid  is  oxidized 
completely  to  carbonic,  oxalic,  and  acetic  acids  by  alkaline  permanga- 
nate. 

Cochenhausen3  and  Witzemann4  also  have  studied  the  action  of  alkaline 
potassium  permanganate  on  acetone.  Both  worked  at  room  temperature 
and  both  added  the  solid  permanganate  to  the  acetone  in  alkaline  solution. 
Cochenhausen  used  an  excess  of  the  oxidizing  agent  and  then  decolorized 
with  sodium  peroxide.  Witzemann' s  work  and  the  results  embodied  in 
this  paper  show  that  unchanged  acetone  is  likely  to  be  present  in  the  solu- 
tion under  the  conditions  of  Cochenhausen 's  experiment,  but  Cochen- 
hausen has  not  taken  into  account  the  fact  that  any  such  unchanged  ace- 
tone will  be  attacked  by  sodium  peroxide.  Denis5  oxidized  with  both 
neutral  and  alkaline  permanganate  acetone  as  well  as  acetol,  mesoxalic 
acid,  and  other  compounds  directly  related  to  acetone. 

In  general,  there  is  a  unanimity  of  opinion  concerning  the  character 
of  the  products  obtained  from  the  oxidation  of  acetone  by  potassium  per- 
manganate, that  is,  that  they  consist  of  carbonic,  oxalic,  and  acetic  acids, 
with  pyruvic  acid  if  the  oxidation  takes  place  at  a  temperature  below 
20°  C.  Pastareau,6  by  using  hydrogen  peroxide  in  acid  solution,  obtained 
acetone  peroxide,  acetylcarbinol  and  pyruvic  acid;  but,  with  this  one 
exception,  not  permanganate  alone,  but  all  oxidizing  agents  whether  used 
in  alkaline  or  acid  medium,  have  yielded  with  acetone,  acetic,  carbonic, 
oxalic  and  pyruvic  acids  as  final  products.  There  is  the » widest  diver- 
gence, however,  in  the  quantitative  results  of  the  various  oxidations  but 
that  is  to  be  expected  when  one  considers  the  differences  in  the  conditions 
under  which  the  various  pieces  of  work  were  done. 

1  Bull.  Soc.  Chim.,  3,  259  (1908). 

2  Compt.  Rend.,  140,  1591  (1905). 

3  Jour,  fur  prakt.   Chem.,  58,  454  (1898). 

4  Jour.  Am.   Chem.  Soc.,  39,  2657   (1917). 

5  Am.  Chem.  Jour.,  38,  561  (1907). 

6  Loc.  cit. 


16 

2.    Experimental  Part. 

Materials — Acetone.  The  acetone  used  had  been  made  from  the  bisul- 
fite addition  compound.  The  purity  of  it  was  tested  by  four  methods. 

Boiling  point.  The  results  from  this  were  not  satisfactory.  An 
oil  bath  was  used  and  its  temperature  maintained  between  65°  C.  and 
70  °  C.  The  boiling  point  of  the  acetone  ran  from  53  °  C.  to  58  °  C.  (Olsen 
56-57°  C.) 

Specific  gravity  determinations.  These  were  made  by  a  pyknom- 
eter  standardized  at  20°  C.  and  gave  an  average  value  of  0.7924.  (Olsen 
—0.7900.) 

Anhydrous  copper  sulfate  test.  A  sample  in  contact  with  an- 
hydrous copper  sulfate  showed  a  distinct  blue  color  after  a  few  hours. 

Titrimetric  Evaluation.  A.  J.  Field1  after  testing  the  various 
methods  for  the  determination  of  acetone,  recommended  the  Robineau- 
Rollins  Method  as  modified  by  Kebler.2  This  method  was  used.  Briefly 
the  procedure  is:  Add  to  20  cc.  of  an  alkaline  potassium  iodide  solution 
a  measured  sample  of  an  aqueous  acetone  solution  and  from  a  burette  run 
in  while  rotating  the  flask  an  excess  of  sodium  hypochlorite  solution. 
After  one  minute  acidify  the  solution  with  hydrochloric  acid  and  titrate 
with  sodium  thiosulfate  solution. 

By  this  method  the  acetone  showed  a  purity  of  97.53  per  cent.  237.180 
grams  of  it  were  weighed  out  from  a  weighing  burette  and  made  up  to 
1000  cc.  with  carbon  dioxide-free  water.  This  made  an  approximately 
4  molar  solution  (1  cc.  =  0.2313  g.  acetone). 

All  other  materials  used  were  the  same  as  those  used  for  oxidation  of 
isopropyl  alcohol. 

Methods — Oxidation.  The  acetone  was  oxidized  in  the  same  manner 
as  the  isopropyl  alcohol. 

Determination  of  acetone.  In  the  samples  of  low  alkalinity  of  the 
50°  C.  series  and  in  all  of  the  samples  of  the  25°  C.  series  excess  acetone 
was  found.  This  excess  acetone  was  not  a  matter  of  chance  in  titrating; 
it  seems  to  be  necessary  at  lower  temperature  and  alkalinities  in  order 
to  bring  about  the  complete  reduction  of  the  permanganate.  The  amount 
of  excess  varies  inversely  with  the  alkalinity  and  the  temperature.  Witze- 
mann's3  results  support  this  statement.  The  Robineau-Rollins-Kebler 
method  already  described  was  used  for  the  estimation  of  the  unchanged 
acetone.  In  those  samples  in  which  the  acetone  content  was  very  low  the 
salicylaldehyde  test  was  used. 

Carbon  dioxide,  oxalic  acid,  and  acetic  acid  were  determined  exactly 

1  Jour.  Ind.  Eng.  Chem.,  10,  552  (1918). 

2  /.  Am.   Chem.  Soc.,  19,  316  (1897). 

3  Loc.  cit. 


17 

as  described  under  isopropyl  alcohol.  In  connection  with  the  determina- 
tion of  oxalic  acid  a  separate  experiment  was  made  to  prove  the  action  of 
permanganate  on  an  acid  solution  of  acetone.  One  hundred  cubic  centi- 
meters of  a  2  per  cent  solution  of  acetone  containing  5  cc.  of  sulfuric  acid 
(1:4)  and  heated  to  80°  C.  remained  pink  for  several  hours  after  the  ad- 
dition of  two  drops  of  a  tenth-normal  permanganate  solution. 

3.     Results. 

The  results  of  analyses  are  shown  in  three  different  ways:  By  tables; 
by  ordinary  curves;  by  logarithmic  curves. 

The  tables  of  numerical  data  on  the  next  pages  are  self-explanatory. 
Because  of  the  difficulty  encountered  in  titrating  the  permanganate  solu- 
tion to  exactly  the  proper  end  point,  many  of  the  samples  were  checked 
three  or  four  times.  From  the  amounts  of  oxalic,  acetic,  and  carbonic 
acids  shown  in  columns  5,  6,  and  7  were  calculated  the  amounts  of  these 
substances  which  would  be  produced  by  0.1  Mol.  of  acetone  (5.805  g.) 
under  the  same  conditions.  These  calculated  results  are  given  in  columns 
9,  10,  and  11.  They  are  used  with  the  alkali  concentrations  in  drawing 
the  graphs  and  logarithmic  curves. 

Obviously  the  alkali  concentration  will  be  a  constantly  changing  factor 
in  these  experiments  and  one  must  choose  between  defining  it  as  the  "ini- 
tial concentration,"  the  "final  concentration"  and  the  "average  concen- 
tration" (calculated).  If  one  desires  to  employ  the  latter  term,  he  must 
take  several  factors  into  account: 

(1)  The  volume  of  acetone  solution  tends  to  decrease  the  concentra- 
tion of  the  alkali.  With  the  exception  of  samples  1,  2,  and  3  at  25°  C. 
this  volume  is  so  small  (10—15  cc.)  that  it  might  properly  be  disregarded. 

(2)  The  decomposition  of  the  permanganate  (2KMnO.  +  HOH — >2KOH 
+  2MnO2  +  3O)  is  constantly  increasing  the  alkali  content  of  the  samples. 

(3)  As  the  various  acids  are  produced  part  of  the  alkali  is  used  for  their 
fixation  thus  lessening  the  amount  of  free  alkali.     (4)  Part  of  the  alkali 
is,  according  to  Morawsky  and  Stingl,1  present  in  the  brown  sludge  as 
Mn4KH3Oi0.     This  point  is  regarded  as  open  to  argument,  however,  by 
later  authorities.      Considering  the  variability  of  these  factors  at  any  given 
points  in  the  reaction  a  calculation  of  the  "average  alkali  concentration" 
could  be  only  a  rude  approximation.     It  was  considered  advisable,  there- 
fore to  use  the  "initial  concentrations"  and  these  are  given  in  column  1  of 
each  series. 

A  peculiar  situation  exists  in  the  "neutral"  samples  with  reference  to 

alkalinity.    In  the  beginning  they  have  a  neutral  reaction — at  the  end  of  the 

experiment  a  decidedly  alkaline  reaction.     This  means,  of  course,  that 

a  part  of  the  general  reaction  took  place,  not  in  a  neutral,  but  in  an  alka- 

1  Jour,  prakt.  Chem.,  18,  82  (1878). 


*s 

dfl 

£g 

*bk 

60  6 
£«£ 

No.  g. 
acetone 
introduced 

No.  g. 
unchanged 
acetone 

No.  g. 
acetone 
oxidized 

18 
ACETONE 

•c             *c 

<u                <u 

m  !§? 

H 

C-c 

!i 

m 

% 

carbon 
recovery 

Calculated  yields 
for  0.1  Mol.  of 
Acetone  (5.8036  g.) 

C204 

CO2    CHsCOOH 

Temperature  25°  C. 

1 

0.00 

12.340 

9.067 

3.273 

0.371 

2.292 

3.156 

98.03 

0.656 

4.056 

5.586 

2 

0.50 

5.718 

2.522 

3.196 

1.397 

2.685 

2.046 

97.43 

2.537 

4.876 

3.716 

3 

1.06 

4.607 

1.916 

2.691 

2.026 

2.156 

1.192 

96.89 

4.370 

4.650 

2.571 

4 

2.12 

3.137 

0.596 

2.541 

2.572 

1.976 

0.817 

99.20 

5.874 

4.505 

1.340 

5 

3.18 

2.832 

0.285 

2.547 

3.074 

1.916 

0.416 

97.12 

7.009 

4.369 

0.948 

6 

5.32 

2.631 

0.121 

2.510 

3.258 

1.885 

0.330 

98.64 

7.533 

4.358 

0.763 

7 

10.64 

2.561 

0.081 

2.480 

3.312 

1.855 

0.331 

100.20 

7.751 

4.341 

0.774 

8 

21.28 

2.561 

0.054 

2.507 

3.325 

1.880 

0.329 

99.74 

7.701 

4.354 

0.778 

9 

85.12 

2.531 

0.031 

2.500 

3.329 

1.872 

0.336 

100  ..13 

7.733 

4.349 

0.780 

Temperature 

50°  C. 

1 

0.00 

3.470 

0.428 

3.042 

0.565 

3.075 

2.156 

98.36 

1.079 

5.868 

4.116 

2 

0.50 

3.220 

0.592 

2.628 

2.004 

2.761 

0.783 

98.90 

4.426 

6.095 

1.729 

3 

1.06 

2.794 

0.251 

2.543 

2.427 

2.393 

0.545^ 

97.34 

5.540 

5.462 

1.242 

4 

2.12 

3.470 

0.925 

2.545 

2.866 

2.049 

0.469 

97.50 

6.554 

4.679 

1.080 

5 

3.18 

2.961 

0.434 

2.527 

3.196 

1.910 

0.330 

97.58 

7.314 

4.384 

0.758 

6 

5.32 

2.535 

0.000 

2.535 

3.342 

1.915 

0.291 

98.66 

7.651 

4.399 

0.662 

7 

10.64 

2.487 

0.000 

2.487 

3.419 

1.871 

0.241 

99.72 

7.982 

4.371 

0.560 

8 

21.28 

2.494 

0.000 

2.494 

3.388 

1.900 

0.238 

99.42 

7.906 

4.422 

0.553 

9 

85.12 

2.487 

0.000 

2.487 

3.410 

1.897 

0.242 

100.80 

7.958 

4.428 

0.543 

Temperature  75°  C. 

1 

0.00 

2.644 

0.0 

2.644 

0.910 

3.400 

1.064 

97.92 

1.998 

7.466 

2.344 

2 

0.50 

2.463 

0.0 

2.463 

1.892 

2.925 

0.429 

97.33 

4.562 

6.894 

1.011 

3 

1.06 

2.465 

0.0 

2.465 

2.242 

2.759 

0.382 

99.23 

5.275 

6.495 

0.900 

4 

2.12 

.2.457 

0.0 

2.457 

2.752 

2.322 

0.363 

99.98 

6.502 

5.483 

0.856 

5 

3.18 

2.461 

0.0 

2.461 

3.132 

2.068 

0.308 

100.90 

7.388 

4.877 

0.725 

6 

5.32 

2.463 

0.0 

2.463 

3.299 

1.928 

0.273 

100.50 

7.775 

4.542 

0.643 

7 

10.64 

2.463 

0.0 

2.463 

3.394 

1.918 

0.210 

100.40 

7.977 

4.521 

0.493 

8 

21.28 

2.452 

0.0 

2.452 

3.393 

1.896 

0.205 

100.30 

8.020 

4.485 

0.483 

9 

85.12 

2.457 

0.0 

2.457 

3.388 

1.909 

0.204 

100.10 

8.007 

4.513 

0.481 

line  medium.  Adkins1  found  in  oxidizing  acetaldehyde  in  "neutral"  solu- 
tion that  the  solution  was  faintly  acid  at  the  end  of  the  reaction  due  to 
the  presence  of  carbon  dioxide.  Chapman  and  Smith2  in  a  report  of 
their  work  with  ethyl  alcohol  and  neutral  permanganate  go  into  detail 
concerning  this  change  of  reaction. 

"The  fact  is,  the  neutral  permanganate  is,  by  the  abstraction  of  1  equiv- 
alent of  oxygen  in  the  presence  of  water,  converted  into  1  equivalent  of 

1  Loc.  cit. 

2  Jour.  Chem.  Soc.,  20,  301  (1867). 


19 

manganate  of  hydrated  manganic  acid which  at    once  splits 

up  into  binoxide  of  manganese  and  oxygen.  From  this  it  appears  that 
two-thirds  of  the  available  oxygen  of  the  permanganate  may  be  removed 
without  in  any  way  affecting  the  neutrality  of  the  solution.  But  as  in 
this  reduction  acids  are  formed,  an  even  larger  quantity  of  oxygen  may 
be  removed  from  the  permanganate  before  the  solution  has  become  really 

alkaline We  have,  in  fact,  a  most  complicated  series  of 

reactions;  first,  action  in  a  neutral  solution;  second,  action  in  a 

possibly .acid  solution,  and  third,  action  in  a  alkaline  solution." 

These  authors  suggest  the  use  of  manganate  rather  than  permanganate 
as  a  means  of  obtaining  a  more  regular  set  of  conditions. 

The  character  of  the  manganese  sludge  and  its  mode  of  formation  was 
much  the  same  as  described  by  Day.1  In  the  samples  of  high  alkalinity 
the  manganese  oxides  were  reddish  brown  and  had  a  tendency  to  be  floc- 
culent;  in  the  samples  of  low  alkalinity  the  sludge  formed  more  slowly 
and  was  an  exceedingly  fine,  almost  black  powder.  In  the  neutral  solu- 
tions at  25°  C.  and  50°  C.  the  oxides  appeared  to  be  present  as  colloidal 
matter  for  as  long  as  two  days — then  gradually  precipitated  out. 

Adkins2  speaks  of  the  fact  that  in  the  faintly  acid  solutions  resulting 
from  oxidations  in  a  "neutral"  medium,  large  masses  of  organisms  appeared 
after  a  few  days.  The  same  thing  was  observed  in  occasional  samples 
of  this  work  but  seemed  to  be  a  freak  effect — that  is,  the  growths  were  as 
likely  to  develop  in  a  sample  of  high,  as  of  low,  alkalinity  and  many  of 
the  samples  showed  no  trace  of  them  after  standing  for  weeks.  More- 
over, such  growths  seemed  to  have  no  effect  upon  the  content  of  the  sam- 
ples in  which  they  developed :  analyses  made  several  weeks  apart  checked 
closely. 

Evans  and  Day2  and  Evans  and  Adkins2  proved  that  the  rate  of  the 
addition  of  the  reducing  agent  made  no  difference  upon  the  amounts  of 
the  reducing  solution  required  nor  upon  the  amounts  of  the  oxidation 
products  obtained.  Preliminary  experiments  showed  that  this  was  not 
true  of  acetone.  Samples  to  which  the  acetone  solution  had  been  added 
rapidly  yielded  more  oxalic  and  less  carbonic  acid  than  samples  to  which 
the  solution  had  been  added  slowly.  To  test  the  point  three  experiments 
were  made  at  75°  C.,  each  containing  5.32  g.  of  alkali.  To  the  first  one 
cc.  of  the  reducing  solution  was  added  every  fifteen  minutes ;  to  the  second, 
one  cc.  every  thirty  minutes;  and  to  the  third,  one  cc.  every  sixty  minutes. 
The  differences  between  the  amounts  of  acetone  required  were  well  within 
the  limit  of  experimental  error  but  the  amounts  of  oxalic  acid  which  they 
yielded  varied  appreciably.  The  first  gave  0.906  g.,  the  second  0.898  g. 

1  Day:  Thesis,  1916,  p.  36. 

2  Loc.  cit. 


20 

and  the  third  0.879  g.  This  evidence  is,  of  course,  too  scanty  to  serve  as 
a  basis  for  any  general  conclusions  but  taken  in  connection  with  previous 
observations  and  with  the  very  significant  results  obtained  with  butyl 
alcohol,1  it  indicates  the  advisability  of  a  regular  addition  of  acetone. 
The  rate  already  given — one  cc.  every  half  hour — was  used  throughout  the 
work  of  this  paper. 

No  attempt  was  made  to  go  further  with  the  problem  of  the  rate  of 
reaction.  That  constitutes  a  field  in  itself.  Some  work  has  already 
been  done  on  it.  Dreyfus2  working  in  acid  solution  and  using  ethyl  alco- 
hol as  a  standard,  determined  the  rates  of  reaction  for  several  organic  sub- 
stances. 

Castle  and  Loevenhart3  oxidized  formic  aldehyde  with  alkaline  hy- 
drogen peroxide  in  order  to  determine  the  rate  of  reaction.  A  more  am- 
bitious piece  of  work  was  undertaken  by  C.  W.  R.  Powell.4  He  studied 
the  rate  of  reaction  of  sucrose  with  alkaline,  acid,  and  neutral  perman- 
ganate. In  acid  solution  his  results  indicated  a  bi-molecular  reaction 
although  he  found  that  the  velocity  coefficient  increased  during  the  course 
of  the  reaction. 

Figs.  2,  3,  and  4  show  the  products  from  oxidations  made  at  25°  C., 
50°  C.,  and  75°  C.,  respectively,  plotted  against  initial  alkali  concentra- 
tions. Fig.  5  shows  oxalic  acid  yields  from  oxidations  at  the  three  tempera- 
tures given;  Fig.  6  the  carbonic  acid  yields  and  Fig.  7  the  acetic  acid  yields. 
Logarithmic  curves  corresponding  to  those  are  given  in  Figs.  8,  9, 
and  10. 

Reference  has  been  made  to  the  fact  that  there  is  a  difference  of  opinion 
concerning  the  action  of  neutral  permanganate  solution  on  acetone.  Some- 
time after  St.  Gilles5  made  the  statement  that  acetone  was  unaffected  by 
permanganate  solution,  F.  Sachs6  used  boiling  acetone  as  a  medium  for 
affecting  the  oxidation  of  certain  benzyl  compounds  with  permanganate. 
Martines7  used  a  solution  of  permanganate  in  acetone  for  the  oxidation 
of  menthones.  The  most  recent  published  work  on  acetone8  confirms 
the  findings  of  St.  Gille,  Sachs,  and  Martines.  Witzemann  added  solid 
permanganate  to  a  neutral  solution  of  acetone  and  allowed  it  to  stand 
for  several  weeks.  At  the  end  of  that  time  there  was  no  indication  of 
action  between  the  two  substances. 

1  Supplement  to  this  thesis. 

2  Compt.  Rend.,  105,  523. 

3  J.  Am.   Chem.  Soc.,  21,  262  (1899). 

4  Jour.  Proc.  Roy.  Soc.  N.  S.  Wales,  48,  11,    223. 

5  Loc.  cit. 

e  Ber.,  34,    497  (1904). 

7  Ann.  Chem.  et  phys.,  Ser.  8,  3,  82  (1904). 

8  Witzemann,  Loc.  cit. 


21 


o 


^e 


VtKr 

4R^ 


w 


3^ 


ME 


-W 


No.  GRAMS    KOH 
Fig.  1 


10 

6 

cT 

CJ 
<o  . 

\ 

H 

X 

-A. 

A 

SI 

0 

2 

t 

f^ 

5 

'U 

c 

p 

R 

Q 

II 

r 

AC 

"| 

^ 

^ 

f 

"P 

(-} 

M 

u 

•l  p 

fl 

-u 

i  r 

, 

)  (^ 

Jl 

K 

^C 

1 

L 

/ 

^U 

L 

Jl 

IL 

L 

, 

^  j 

n 

f\ 

ip 

1 

*• 

L 

3  12  15 

No.  GRAMS  KOH 

Fig.  2 


22 


8 

6 

r 
o 
o 

0 

m 

0 

$< 

d 

2 

\ 

*r 

e 

i  n 

1 

P 

,L 

K 

' 

l^ 

It 

_,  . 

^h 

/i 

^^ 

ji 

1 

1 

i  r 

P 

PI 

s^ 

I 

-\  i 

i  r 

^ 

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)\ 

N. 

u 

i 

/ 

Ll 

JI 

1C 

,-, 

i 

M 

^ii 

\ 

^ 

s^ 

^ 

, 

5 

0 

C 

7 

5" 

3                     6                    9                    12                    IS                    18                   21                   A 

No.  GRAMS    KOh 

Fig.  3 


Los  Nos.-  KOH 
Fig.  4 


23 


RO 


Los  Nos. -KOH 
Fig-  o 


15 


HOI 


,Loe  N05.-KOH 
Fig.  6 


24 


Fig.  7 


8 

0" 
o 

^ 

I 

v 

g 

«o6 

(D 
Z4 

\! 

^ 

\ 

^ 

s 

fcv 

X 

^« 

.  

.  _ 

2 

P 

->  r 

9  r 

t\ 

If 

c 

^ 

IL 

c 

r 

P, 

M 

/\ 

p 

P 

"^r 

IF" 

*- 

n 

. 

in 

' 

D 

3                    6                   9                   12                   15                   18                  21                   fl 

No.  GRAMJ    KOH 

Fig.  8 


25 


fTt 


OM 


V3 


> 


9  IZ  15 

No.  GRAMS   KOH 
Fig.  9 


8fi 


dT 

t_T 

i 

<o 

0 

Z 

0 
0 

_J 

| 

<sa 

s=^ 

^ 

==1 

r4 

x 

^=J 

=tf 

•v^ 

-y 

«)" 

L 

.^^ 

^ 

s- 

x 

•<: 

p° 

x 

*= 

^•^ 

3 

X 

/ 

Pi 

x/ 

0 

r 

p 

IP 

^x" 

A 

L 

iL 

1C 

«s 

X 

p 

p 

-\  N 

A 

t 

,x 

1 

X1 

rt 

^r 

T1 

r^y 

M 

-^ 

^ 

U 

Los  Nos-KOH 
Fig.  10 

26 


LOG  Nos.  -  KOH 
Fig.  11 


31 
0 
0 
0 
K) 

X 

u 

<o 
o 

z: 

^> 
o 

_i 

1 

t 

r 

-r 

if 

A 

~ 

•^ 

' 

* 

X 

T 

r 

rs 

\ 

\ 

f\ 

p 

p- 

Tf 

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IP 

S^ 

0 

1 

L 

L- 

Jl 

NL 

s 

^ 

2 

LT 

\ 

X, 

s 

^ 

v- 

v^ 

\ 

~* 

^N 

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0 

\ 

^C 

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3 

LJ 

~^ 

5 

X 

^ 

^. 

1 

s^ 

•^-^ 

.  

? 

T0 

^ 

v^. 

s 

^ 

—  ^ 

—  - 

-£ 

^ 

•—  - 

-— 

Ck 

^, 

^  — 

^ 

LOG  Nos.-  KOH 
Fig.  12 

27 

Hercz,1  on  the  other  hand  found  that  acetone  was  oxidized  to  acetic  acid 
and  carbon  dioxide  by  neutral  permanganate.  Fournier2  says  that  "pure 
acetone  is  oxidized  very  slowly  by  a  neutral  solution  of  permanganate," 
and  Denis,3  upon  heating  acetone  with  an  excess  of  neutral  permanganate 
at  50°-55°  C.,  obtained  oxalic,  carbonic,  and  acetic  acids  in  quantitative 
amounts .  The  work  of  this  paper  is  in  accordance  with  the  results  obtained 
by  the  last  named  investigators.  At  no  time  and  at  no  temperature  was 
there  any  doubt  that  the  acetone  was  being  attacked  altho  the  reaction 
at  all  three  temperatures  was  very  much  slower  than  that  of  samples  ini- 
tially alkaline  and  at  25°  C.  and  50°  C.  and  excess  of  the  acetone  was 
necessary  to  bring  about  complete  reduction.  In  the  neutral  sample  at 
25°  C.  this  excess  of  the  acetone  was  necessary  to  bring  about  complete 
reduction.  In  the  neutral  sample  at  25°  C.  this  excess  amounted  to  nearly 
three  times  the  amount  actually  consumed  and  four  days  were  required 
for  complete  reduction.  In  another  sample  at  25°  C.  the  excess  was 
approximately  equal  to  the  amount  used,  but  twelve  days  were  required 
for  complete  reduction.  The  oxalic  acid  content  of  the  two  reaction- 
products  checked  very  closely. 

There  are  several  possible  reasons  for  the  varying  results  obtained  by 
different  investigators : 

1.  The  action  observed  by  Hercz,5  Fournier,3  and    the    author  of 
this  paper  may  be  due  to  the  fact  that  the  acetone  used  contained 
some  impurity  which  initiated  a  slight  decomposition  of  the  permanganate 
thus  establishing  an  alkaline  condition.     It  seems  hardly  likely,  however 
that  St.  Gilles,  for  instance,  would  be  able  to  obtain  a  purer  product  than 
Hercz  or  Fournier. 

2.  Witzemann3  added  the  solid  permanganate  a  little  at  a  time  to  a 
definite  amount  of  acetone  solution.     In  this  work  the  acetone  solution 
was  added  at  regular  intervals  to  a  fixed  amount  of  permanganate.     That 
a  difference  in  the  order  of  addition  of  the  reagents  makes  a  difference 
in  the  quantitative  results  is  shown  in  the  supplement  to  this  paper.     It 
may  be  that  this  difference,  in  the  case  of  acetone,  is  extended  to  a  differ- 
ence in  the  character  of  the  products.     Work  testing  this  point  is  under  way. 

3.  It  happens  sometimes  that  there  are  in  certain  laboratories  minute 
quantities  of  bodies  which   exert  a  catalytic  effect  on  a  given  reaction 
when  these  bodies  are  absent,  the  reaction  goes  on  in  an  entirely  different 
manner.     Professor  C.  W.  Foulk  of  this  laboratory  cites  two  examples  of 
this  which  came  under  his  personal  observation — one  which    accounted 
for  differences  observed  by  Professor  N.  W.  Lord  of  Ohio  State  University 

1  Lieb.  Am.,  186,  257  (1877). 

2  Butt.  soc.  Chem.,  3,  259  (1908). 

3  Loc.  cit. 


28 

and  Doctor  Cain  of  the  Bureau  of  Standards  and  the  other  for  differences 
observed  by  Ostwald  and  Bredig.  Possibly  the  same  explanation  may 
serve  as  a  reason  for  the  differences  in  question. 

4.  Differences  in  the  concentration  of  the  reacting  materials  may 
account  for  the  recorded  differences  in  behavior.  Sachs1  and  Martines1 
dissolved  the  permanganate  crystals  in  pure  acetone  and  found  that  it 
was  without  effect  upon  the  acetone.  Fournier1  with  a  neutral  solution 
of  permanganate  and  pure  acetone  observed  a  slow  oxidation.  Hercz1 
also  used  a  solution  of  permanganate  and  obtained  an  oxidizing  action. 
Witzemann1  on  the  other  hand,  noted  no  change  when  crystals  of  per- 
manganate were  added  to  an  acetone  solution,  while  Denis1  and  the  author 
of  this  paper  by  using  both  the  permanganate  and  the  acetone  in  aqueous 
solution  were  able  to  oxidize  the  acetone.  In  view  of  this  data  it  seems 
hardly  likely  that  the  dissociating  action  of  water  in  itself  initiates  the 
action. 

4.       Discussion  of  Results. 

Evans  and  Day1  have  summed  up  very  completely  the  evidence  which 
shows  (1)  that  oxalic  acid  is  not  formed  from  acetates  and  (2)  that  car- 
bonic acid  is  not  formed  from  oxalates  nor  acetates  under  the  conditions 
which  obtained  for  the  work  of  this  paper.  The  tables  and  curves  show 
that  all  three  of  these  substances  are  formed  when  acetone  is  oxidized  by 
either  neutral  or  alkaline  permanganate. 

Effect  of  varying  initial  alkalinity. — 1.  As  with  isopropyl  alcohol, 
the  amounts  of  acetic  and  carbonic  acids  produced  are  inversely  propor- 
tional to  the  initial  alkalinity.  2.  The  amounts  of  oxalic  acid  vary  di- 
rectly with  the  alkalinity.  3.  After  the  initial  alkalinity  has  reached 
a  value  of  six  to  eight  grams  per  liter  it  produces  a  constant  instead  of 
a  varying  effect  upon  the  production  of  the  various  acids. 

For  an  explanation  of  these  results  it  is  necessary  to  consider  the  dis- 
sociation possibilities  of  acetone: 

Such  a  dissociation  does  not  provide  for  the  formation  of  oxalic  acid— 
a  substance  which  is  shown  to  be  one  of  the  end-products  when  acetone 
is  oxidized. 


CH3  CH3 


OH     +      X 


CO  c    /  ^CH2 

CH3 

\ 


1  Loc.  tit. 


29 


2.   CH3 

1 

CH3 

j 

CH3 

1 

CH3 

1 

1 
CO   —  > 

x 

! 
CO 

1 

1 
—  >   CO   —  > 

1 

1 
CO 

1 

1      x 

CH3 

/CH 

I 

CHO 

1 

COOH 

That  pyruvic  acid  is  formed  by  the  oxidation  of  acetone  is  proven  be- 
yond a  doubt  by  Fournier1  and  confirmed  by  both  Denis1  and  Witzemann. 2 
The  last  two  investigators  account  for  its  production  however  by  the  enal- 
ization  of  acetone  (see  possibility  4). 


3.       CH3 
CO 

I 

CH5 


>i 


CO 


>! 


CHO 
CO 
CHO 


If  acetone  dissociated  in  this  way  no  acetic  acid  would  be  formed,  hence 
this  possibility  is  excluded. 

4.  Denis-Witzemann  Reaction. — Witzemann3  on  the  basis  of  his  own 
work  and  that  of  Denis3  on  acetone  and  related  substances  had  presented 
the  following  as  the  probable  mechanism  for  the  oxidation  of  acetone  by 
alkaline  permanganate: 


CH3 

1 
CO 

1 

CH2                         CH2OH                         CH2OH 

II                              1                                     1 
>         C(OH)      >      C(OH)2        >        CO         >• 

1                                      I 

1 
CH3 

COOH 

1 

CH3                        CH3 
^CHsCOOH  +  CO-j 

/ 

1 
CH3 

1 
CO 

1 

CH3 

/ 

COOH                  COOH 

\    I 
>C(OH)     —  >     C(OH2) 

COOH              COOH 

1 
—  >     CO      —  >>      COOH 

CH2                       CH20 

CH2OH 

1  Loc.  cit. 

2  J.  Am.  Chem.  Soc.,  739,  p.  2666. 

3  Loc.  cit. 


C02 


30 

He  calls  attention  to  the  fact  that  every  step  of  this  mechanism  has 
been  backed  by  experiment  except  the  enolization  of  the  pyruvic  acid. 
Denis,1  whom  he  cites  as  authority,  worked  mostly  at  room  temperature 
and  used  samples  whose  initial  alkalinity  ranged  from  0.0  to  30.0  grams 
KOH  per  liter.  Assuming  tentatively  the  correctness  of  this  mechanism 
under  such  conditions  let  us  consider  the  effect  (1)  of  decreasing  alkalinity; 
and  (2)  of  increasing  temperature. 


CH3 

I 
CO 

I 
CH3 


CH2  CH2OH 

||     +0  +HOH    | 
C(OH)     — >        C(OH)2 


CH3 


CH3 


CH2OH 

I 
CO 

I 

CH3 


CH3.  COOH+C02 

CH2  COOH 

C(OH)  CO 

I  I 

COOH  COOH 


COOH 


COOH 


C02 


Effect  of  Alkalinity. — An  examination  of  the  curves  shows  that  in  gen- 
eral, a  decrease  in  the  alkalinity  produces  an  increase  in  the  amount  of 
carbonic  acid  produced. 

Suppose  the  decrease  in  alkalinity  shifted  the  reaction  so  that  it  fol- 
lowed entirely  course  1 — suppose  it  caused  it  to  go  entirely  in  the  direction 
of  2 — suppose  it  goes  partly  (any  proportion)  in  one  direction  and  partly 
in  another :  in  any  of  the  three  cases,  two  molecules  of  carbonic  acid  would 
be  produced  respectively  for  every  two  of  acetic  or  for  every  two  molecules 
of  carbonic  acid  or  for  every  one  molecule  of  oxalic  and  one  of  acetic,  and 
that  would  mean  a  straight  line  for  the  carbonic  acid  provided  the  amounts 
of  acetone  used  for  the  reduction  of  the  sample  were  practically  the  same. 

But  the  carbonic  acid  production  in  samples  containing  less  than  7 
grams  KOH  per  liter  when  plotted  against  initial  alkalinity,  do  not  give 
straight  lines  and  the  differences  in  the  amounts  of  acetone  used  are  not 
nearly  great  enough  to  account  for  the  curve  which  they  make.  It  fol- 
lows then  that; 

1.     There   is  accompanying    the  Denis- Witzemann  reaction,   some 
other  reaction  that  yields  a  larger  proportion  of  carbonic  acid  or  that 
1  Loc.  cit. 


31 

2.  In  samples  of  low  alkalinity,  some  product  of  the  Denis- Witze- 
mann  reaction  is  yielding*  carbonic  acid  or  that 

3.  A  combination  of  these  two  factors  produces  the  effect  observed. 
In  a  piece  of  work  recently  completed  at  Ohio  State  University  by 

O.  C.  Hoover,  it  has  been  shown  when  acetol  in  neutral  solution  is  oxidized 
under  the  same  conditions  as  those  which  obtained  in  this  work,  five-sixths 
of  the  carbon  appeared  in  trie  form  of  CO2,  and  further,  that  the  amount 
of  carbon  appearing  as  CO2  decreased  with  increasing  alkalinity  of  the 
samples. 

According  to  the  Denis- Witzemann  reaction  acetol  (which  appears  as 
the  third  product  of  oxidation)  would  yield  only  one-half  of  its  carbon 
as  CO2.  It  is  fairly  certain  then  that  in  samples  of  acetone  at  low  alka- 
linity, the  reaction  follows  some  other  course  than  that  indicated  by  "pos- 
sibility 4." 

Suppose  acetol  dissociated  thus: 

CH3  CH3 

+        H2CO 
CO       — >       CHO 

I 
CH2OH 

One-third  of  the  carbon  only  could  appear  as  CO2  in  this  case.  But  if  we 
conceive  of  at  least  a  part  of  the  CH3.CHO  dissociating  into  methylene 
and  formaldehyde: 

CH3  \ 

|  — >  yCH2        +        H2CO 

CHO  / 

then  we  shall  have  accounted  for  the  large  amounts  of  CO2  formed.  Such 
a  dissociation  of  acetol  does  not  provide  for  the  production  of  oxalic  acid 
and  this  is  in  accordance  with  experimental  fact  for  Hoover  obtained  no 
oxalic  acid  from  neutral  samples  of  acetol.  The  fact  that  the  CO2  curve 
from  acetol  is  practically  the  same  as  the  CO2  curve  from  acetone  supports 
the  assumption  that  there  is  accompanying  the  Denis-Witzemann  reaction 
a  side-reaction 

CH2OH  CH3        +          H2CO 

I  I 

CO      >          CHO 

i          \j 

CH3  ")CH2         +  H2CO 

i/ 

and  that  this  reaction  is  suppressed  by  increasing  alkalinity  as  is  to  be 
expected  since  the  substitution  of  the  metals  for  hydrogen  in  compounds 
always  tends  to  stabilize  them.  The  complete  mechanism  may  be  repre- 
sented as  follows: 


32 


CH3    CH2         CH2OH       CH2OH 

I  II  I  I 

CO-*C(OH)->C(OH)2-^  CO 

I  I  I 

CH3    CH3         CH3  CH; 


liyCHa.COOH+COa 
COOH  /   COOH+CO2 
|       /         COOH 
CO  \2i 


CH3          CH2 


COOH 


COOH     COOH 


CH3     +      H2CO 

I 
CHO 

\    * 
p  CH2      +       H2CO 

X 

It  may  be  that  the  excess  of  carbon  dioxide  in  samples  of  low  alkalinity 
is  due  to  the  fact  that  there  is  not,  in  the  beginning  of  the  reaction,  suffi- 
cient alkali  present  to  form  normal  salts  with  the  oxalic  and  carbonic 
acids  produced  and  that  acid  salts  are  formed.  In  that  case,  the  acid 
oxalate  would  break  down  to  CO2  in  the  presence  of  permanganate.  This 
tendency  to  form  acid  salts  would  naturally  grow  weaker  as  the  alkalinity, 
initial  and  induced,  became  greater  and  the  carbon  dioxide  production 
would  fall  off. 

In  the  carbon  dioxide  curves  at  25°  C.  and  50°  C.,  there  is  a  curious 
break  between  the  neutral  samples  and  the  samples  containing  0.5  g. 
alkali  per  liter.  The  most  plausible  explanation  for  this  apparent  irregu- 
larity is  found  by  considering  the  fact  that  at  these  two  temperatures 
neutral  samples  furnish  very  large  amounts  of  acetic  acid,  with  the  sub- 
stance of  the  paper  from  Chapman  and  Smith1  quoted  in  the  first  part  of 
this  article:  "we  have  then  three  sets  of  conditions — neutral  solution, 
acid  solution,  and  alkali  solution."  Is  it  not  possible  that  the  existence 
for  even  a  short  period,  of  acidity  might  suppress  the  formation  of  carbon 
dioxide? 

There  is  another  point  to  be  considered  in  connection  with  this  apparent 
irregularity.  The  crest  of  the  break  may  occur  at  a  point  very  much  nearer 
the  line  of  zero  alkalinity  than  is  indicated.  No  samples  were  estimated 
whose  alkalinity  lay  between  0.0  and  0.5  g.  KOH. 

2.  Effect  of  temperature. — A  study  of  the  curves — Figs.  5,  6,  7 — indicates 

1.      That  the  general  effect  of  increasing  temperature  is  to  send  the 
Denis-Witzemann  reaction  in  direction  2 — that  is,  to  increase  the  pro- 
duction of  oxalic  and  decrease  the  production  of  acetic  acid. 
1  Loc.  cit. 


33 

2.  That  increasing  temperature  has  an  accelerating  effect  upon  the 
speed  of  whatever  factor  or  combination  of  factors  produce  carbon  dioxide. 
If  one  accepts  the  modified  Denis-Witzemann  reaction,  he  will  conceive 
of  a  higher  temperature's  sending  the  reaction  in  the  direction  of  1 — if 
he  prefers  the  second  explanation  of  increased  carbon  dioxide  production, 
then  he  will  have  no  difficulty  in  seeing  that  a  higher  temperature  would 
hasten  the  decomposition  of  acid  oxalates. 

There  yet  remains  a  very  important  fact  to  consider — namely,  that 
acetone  is  oxidized  by  neutral  permanganate  at  all  times.  Denis,1 
although  she  reports  the  production  of  carbon  dioxide,  oxalic  and  acetic 
acids  from  the  action  of  acetone  in  a  neutral  permanganate  solution,  explains 
why  "acetone  will  not  be  attacked  by  neutral  permanganate."  Witze- 
mann1  quotes  this  explanation:  No  isoacetone  molecules  are  present  in  a 
neutral  solution  of  acetone  (three  proofs  of  this  are  given — the  most  obvious 
is  that  acetone  gives  no  precipitate  with  mercuric  salts  while  the  addition 
of  a  minute  quantity  of  alkali  causes  the  precipitation  of  mercuric  iso- 
acetone) and  the  permanganate  will  not  attack  normal  acetone  molecules. 
If  acetone  is  oxidized  by  "neutral"  permanganate  as  we  found  it  to  be, 
then  one  of  two  things  must  be  true:  either  the  acetone  molecule  itself 
is  attacked  or — what  is  more  likely — there  are  present  even  in  neutral 
solutions  of  acetone,  some  isoacetone  molecules  though  not  enough  to  reach 
the  solubility  product  of  mercuric  isoacetone. 

5.    Summary. 

1.  Acetone  is  oxidized  in  both  neutral  and  alkaline  solutions  of  potas- 
sium permanganate  to  acetic  acid,  oxalic  acid  and  carbon  dioxide. 

2.  An  increase  in  the  initial  alkali  concentration  and  in  the  temperature 
increases  the  speed  of  the  reaction. 

3.  The  rate  of  the  addition  of  the  acetone  solution  affects  the  relative 
amounts,  but  not  the  character,  of  the  reaction  products. 

4.  As  the  initial  alkali  content  of  the  samples  increase,  the  amounts 
of  oxalic  acid   increase  until  it  reaches  a  maximum   point.     This   maxi- 
mum effect  is  produced  when  the  alkali  content  is  approximately  seven 
grams  per  liter. 

5.  The  amounts  of  acetic  and  carbonic  acid  grow  less  as  the  initial 
alkalinity  value  increases,  until  a  minimum  effect  (also  corresponding  to 
an  alkalinity  value  of  seven  grams  per  liter)  is  reached. 

6.  An  increase  in  the  temperature  of  the  samples  increases  the  yield 
of  oxalic  acid  and  of  carbon  dioxide  and  diminishes  the  yield  of  acetic 
acid.     In  samples  whose  initial  alkali  content  is  below  seven  grams  per 
liter  the  differences  produced  by  a  change  of  temperature  in  the  carbon 

1  Loc.  cit. 


34 

dioxide  and  acetic  acid  yields  is  considerable,  in  samples  whose  alkali 
content  is  above  seven  grams  per  liter,  very  small,  but  constant. 

7.  The  logarithms  of  the  amounts  of  acetic,  carbonic,  and  oxalic  acids 
are,  within  limits  (from  0.5  to  3.18  g.  KOH  per  liter  of  solution)  linear 
functions  of  the  logarithms  of  the  initial  alkali  concentration. 

III.    THE  OXIDATION  OF  BUTYL  COMPOUNDS 

Three  butyl  compounds — the  normal  alcohol,  aldehyde  and  acid  were 
oxidized.  The  purpose  of  oxidizing  the  butyl  alcohol  was,  as  in  the  case 
of  acetone  and  isopropyl  alcohol,  a  three-fold  one :  to  determine  the  effect 
of  increasing  alkali  concentration  upon  the  character  and  amounts  of  the 
oxidation-products;  to  determine  the  effect  of  increasing  temperature 
upon  the  character  and  amounts  of  the  oxidation-products;  and  to  as- 
certain the  successive  steps  in  the  reaction.  The  butyr aldehyde  and  buty- 
ric acid  were  oxidized  mainly  to  discover  whether  or  not  the  speeds  of  re- 
action were  affected  by  the  rates  of  their  respective  additions  to  the  alka- 
line permanganate  solutions. 

Experimental  Part 

1 .  Materials. — Butyl  alcohol.  The  alcohol  used  was  from  the  Eastman 
laboratories.         It  boiled  at  116.9°  C.  (Beilstein,  116.88  (Kor.)  and  had  a 

/  20° C  \ 

specific  gravity  of  0.8095) .     (  Beilstein  0.8099  at  — ^— '  • )    Owing  to  the  high 

\  20   C.  / 

insolubility  of  the  alcohol  in  water,  the  titrations  were  made  with  pure 
alcohol. 

Butyraldehyde  and  butyric  acid  from  the  Eastman  laboratories  were 
used.  The  butyraldehyde  boiled  at  72.5°  C.  but  the  temperature  con- 
tinued to  rise  to  77°  C.  (Olsen— B.  P.,  73°-74°  C.)  The  butyric  acid 
began  to  boil  at  150°  C.  and  rose  to  165°  C.  The  distillate  which  came 
over  between  160°-165°  C.  was  used,  (Olsen— B.  P.  162°-3°  C.).  Titrations 
were  made  with  the  pure,  rather  than  solutions  of,  the  butyraldehyde  and 
butyric  acid. 

All  the  other  reagents  used  were  made  up  as  described  under  "Isopropyl 
alcohol." 

2.  Methods.  — Much  time  was  spent  in  trying  to  devise  a  method  for  the 
separation  of  the  fatty  acids  whose  presence  in  the  reaction-mixtures  was  con- 
sidered probable.   The  literature  suggests  several  methods  for  the  separation 
of  fatty  acids  but  none  of  these  methods  are  quantitative.     The  following 
procedure  gave  good  results  for  the  determination  of  acetic  acid  and  buty- 
ric acid  in  a  mixture  of  the  two: 

Known  quantities  of  acetic  and  butyric  acids  were  made  up  to  the  mark 
in  a  volumetric  flask.  An  aliquot  portion  was  titrated  with  KOH  solu- 


35 

tion.  Another  aliquot  was  boiled  in  a  reflux  condenser  for  half  an  hour 
with  about  5  grams  of  freshly  precipitated  ammoniacal  silver  oxide.  The 
mixture  was  filtered  while  hot  and  the  filtrate  received  in  weighed  dishes. 
The  solution  was  evaporated  at  35°-40°  C.  and  the  resulting  crystalline 
residue  weighed  and  calculated. 

By  the  use  of  this  method  99.72  per  cent  and  99.75  per  cent  yields  were 
obtained  from  an  acetic  acid  solution  and  butyric  acid  solution  respec- 
tively. When  the  two  are  present  in  a  mixture  the  amounts  of  each  are 
calculated  by  the  "Indirect  Method." 

The  separation  of  butyric  and  acetic  acids  by  means  of  curves  obtained 
by  plotting  the  refractive  indices  of  solutions  of  various  acid  content 
against  the  per  cent  of  acid  content,  was  tried.  To  test  the  practicability 
of  this  method  ten  samples  of  butyric  acid  solution  ranging  from  1  per 
cent  to  0.1  per  cent  strength  were  made  up  and  tested  with  the  Zeiss  re- 
fractometer.  The  1  per  cent  sample  (representing  the  probarJle  maxi- 
mum acid  content  of  samples  from  the  reaction-products)  gave  a  reading 
of  18.0;  the  0.10  sample  a  reading  of  15.3.  Pure  water  gave  a  reading  of 
15.0.  This  range  of  27  points  was  entirely  too  small  to  make  the  method 
a  practical  one  and  the  method  was  abandoned. 

Tests  were  made  on  the  ten  samples  mentioned  above  with  the  West- 
phal  balance  but  once  again  the  range  between  the  density  of  the  strongest 
sample  and  the  weakest  one  was  too  small  to  be  considered  as  a  basis  for 
making  quantitative  determinations. 

In  order  to  be  sure  that  the  substance  calculated  as  oxalate  was  oxalate 
and  not  a  succinate,  an  aliquot  of  the  reaction-mixture  was  boiled  with 
an  excess  of  acetic  acid  (to  remove  CO2O,  treated  with  NH4OH  and  finally 
with  acetic  acid  to  faint  acidity.  A  solution  of  calcium  acetate  was  added, 
the  resulting  precipitate  filtered  on  an  ashless  filter  treated  with  a  few 
drops  of  sulfuric  acid  and  weighed  as  calcium  sulfate.  Another  aliquot 
of  the  same  volume  was  treated  under  the  same  conditions  with  Calcium 
acetate.  The  precipitate  in  this  case  was  dissolved  in  acetic  acid  and  the 
solution  titrated  with  a  permanganate  solution.  The  amount  of  calcium 
present  in  the  calcium  sulfate  was  0.649  gram.  The  amount  of  calcium 
needed  to  unite  with  the  "oxalate"  found  by  the  permanganate  method 
was  0.651.  The  fact  that  these  results  check  fairly  well  makes  it  certain 
that  no  succinic  acid  was  present.  Cahen  and  Hurtley1  when  they  oxi- 
dized sodium  butyrate  with  hydrogen  peroxide  found  fifty  per  cent  of 
the  theoretical  amount  of  succinic  acid  present.  H.  Dakin2  reports  no 
trace  of  succinic  acid  from  an  oxidation  of  ammonium  butyrate  with  hy- 
drogen peroxide  or  does  E.  J.  Witzemann3  from  an  oxidation  of  butyric 

1  Biochem,  Jour.,  11,  164  (1917). 

2  /.  Biol.  Chem.,  4,  77  (1908). 
*Ibid.,   35,   83    (1918). 


36 

acid  in  alkali  solution  with  hydrogen  peroxide.  (The  point  of  these  ref- 
erences is  apparent  when  we  remember  that  butyric  acid  is  undoubtedly 
present  in  a  solution  of  butyl  alcohol  undergoing  alkaline  oxidation.) 

The  oxidation  itself  was  made  in  much  the  same  manner  as  that  of 
acetone  and  isopropyl  alcohol.  All  oxidations  were  made  at  50°  C.  At 
first  about  ten  drops  of  the  pure  reducing  material  was  added  every  fifteen 
minutes.  Later  this  rate  was  varied  in  order  to  note  the  effect  which 
varying  speeds  of  addition  had  upon  the  amounts  required  for  complete 
oxidation. 

An  experiment  was  made  in  which  the  order  of  addition  was  varied. 
A  carefully  weighed  sample  of  butyl  alcohol  (about  9  grams)  was  dissolved 
in  a  liter  of  water  and  to  it  was  added  solid  permanganate,  a  one-half 
gram  at  a  time  until  the  solution  remained  pink  after  standing  over  night. 

3.  Results. — The  "neutral"  solution  of  permanganate  was  faintly  alkaline 
at  the  end  of  the  oxidation.  It  showed  traces  of  carbon  dioxide  and  oxalic 
acid,  and  yielded  large  amounts  of  volatile  acids.  Tests  were  made  on  it  for 
the  aldehydes  but  the  results  were  all  negative.  Carbon  dioxide,  oxalic 
acid  and  volatile  acids  were  found  in  all  the  alkaline  samples. 

The  most  striking  result  and  the  one  which  finally  led  to  the  abandon- 
ment of  the  butyl  compounds  as  reducing  agents  was  this:  it  was  impos- 
sible to  duplicate  results  in  titrating.  A  sample  containing  5.32  g.  KOH, 
for  instance  required  9.56  cc.  of  alcohol  at  one  run;  a  similar  sample  ti- 
trated under  precisely  the  same  conditions  of  temperature  required  9.99  cc. ; 
another  sample  8.26  cc.;  and  another  8.94  cc.  The  same  variations  were 
noted  when  butyraldehyde  and  butyric  acid  were  used  as  reducing  agents. 
Observations  led  to  the  belief  that  this  difference  was  due  to  a  differ- 
ence in  the  rate  of  addition.  To  test  this  point  two  samples  of  perman- 
ganate solution  were  titrated  with  the  alcohol  at  different  rates  of  speed 
and  two  with  butyraldehyde.  Below  are  the  results: 

Reducing  agent  Rate  of  Addition 

Alcohol  5  drops—  15min.  6.13  1.866g. 

Alcohol  5  drops — GOmin.  4.50  1.970g. 

Aldehyde  5  drops— 15  min.  5.50  2.276g. 

Aldehyde  5  drops — GOmin.  4.75  2.237g. 

It  is  obvious  from  the  above  that  the  rate  of  addition  affects  not  only 
the  amounts  of  reducing  material  required  but  also  the  amounts  of  the 
products  obtained.  -  The  titration  of  a  sample  required  from  thirty-six 
to  forty-eight  hours,  making  it  necessary  for  the  solution  to  stand  over 
night.  It  was  impracticable  therefore  to  standardize  the  rate  of  addition 
without  adding  the  alcohol  so  rapidly  that  the  temperature  was  raised 
considerably.  Work  on  the  butyl  compounds  was  therefore  suspended 
until  further  investigations  were  made  on  rate  of  reaction. 


37 

Below  are  given  the  results  from  some  of  the  solutions  titrated: 
0  14.96  0.074  0.005 


5.32     . 

7.27 

1.084 

0.439 

6.825 

87.7 

10.64 

6.83 

1.220 

0.658 

6.342 

89.7 

21.28 

5.87 

1.368 

0.785 

5.096 

88.5 

42.56 

5.27 

1  .  533     i 

0.852 

4.400 

89.3 

85.12 

4.99 

1.868 

0.914 

3.108 

76.0 

85.12 

3.66 

1.971 

1.003 

2.260 

86.3 

170.24 

4.71 

1.981 

1.012 

2.749 

75.7 

These  results  show  that  increasing  initial  alkali  concentration  up  to 
at  least  85.12  g.  KOH  per  liter  affects  the  amounts  of  the  oxidation  prod- 
ucts. 

A  preliminary  examination  of  butyric  acid  showed  that  it  decomposed 
very  rapidly  in  a  strongly  alkaline  solution  of  permanganate.  When 
alkaline  permanganate  solutions  were  titrated  with  butyric  acid,  the  oxi- 
dation proceeded  much  more  slowly  than  similar  oxidation  of  butyl  alcohol 
or  of  butyr aldehyde.  Moreover  when  a  small  amount  of  solid  perman- 
ganate was  added  to  samples  in  which  the  reaction  was  apparently  com- 
plete, the  color  would  disappear  after  a  day  or  two.  Reaction  solutions 
of  the  alcohol  and  permanganate  were  tested  in  this  way  with  the  same 
results,  that  is,  successive  portions  of  additional  permanganate  were  oxi- 
dized slowly.  One  sample  consumed  more  than  5  grams  of  the  perman- 
ganate in  this  way  although  it  required  thirteen  days  for  it  to  lose  its  color 
after  the  last  addition  was  made. 

These  results  suggest  one  reason  why  the  amount  of  alcohol  required 
to  reduce  a  given  quantity  of  permanganate  varies  with  the  rate  of  ad- 
dition. Either  the  butyric  acid  itself  or  some  intermediary  product  is 
oxidized  at  an  exceedingly  slow  rate. 

The  effect  produced  by  changing  the  order  of  the  addition  of  the  oxi- 
dizing and  reducing  agents  was  very  marked.  30  grams  of  permanganate 
(5.32  g.  KOH  per  liter)  required  9.27  grams  of  alcohol  before  its  reduction 
was  complete.  7.27  g.  of  butyl  alcohol  (5.32  g.  KOH  per  liter)  required 
43.271  g.  solid  permanganate  in  order  to  completely  oxidize  it. 

Summary 

1 .  Butyl  alcohol  in  a  neutral  solution  of  potassium  permanganate  yields 
volatile  acids  and  traces  of  oxalic  and  carbonic  acids. 

2.  Butyl  alcohol  yields  volatile  acids,  oxalic  and  carbonic  acids  when 
oxidized  with  alkaline  potassium  permanganate. 

3.  Butyraldehyde  and  butyric  acid  are  oxidized  by  neutral  and  alka- 
line potassium  permanganate. 


38 

4.  The  amounts  of  oxalic  and  carbonic  acids  produced  from  butyl  alco- 
hol vary  directly  with  the  initial  alkali  concentration,  the   amounts   of 
volatile  acids  produced  vary  inversely  with  initial  alkali  concentration. 
The  change  with  varying  alkali  concentration  reaches  a  maximum  when 
that  concentration  is  about  100  grams  KOH  per  liter. 

5.  The  amount  of  reducing  agent  required  varies  inversely  with  the 
speed  of  its  addition. 

6.  The  amount  of  butyl  alcohol  required  to  reduce  a  given  amount  of 
permanganate  as  well  as  the  amounts  of  the  oxalic  acid  produced  is  greatly 
affected  by  the  order  of  addition. 

It  is  a  real  pleasure  to  acknowledge  my  indebtedness  to  Dr.  William 
Lloyd  Bvans  for  his  unfailing  inspiration  and  encouragement.  I  desire 
also  to  thank  Professor  Charles  A.  Foulk  who  very  generously  allowed 
me  the  use  of  his  laboratory,  and  to  express  the  deep  sense  of  appreciation 
which  I  feel  toward  the  memory  of  Professor  Arthur  Marion  Brumback, 
my  Chemistry  teacher  at  Denison  University.  His  was  the  initial  stimulus 
that  gave  rise  to  my  entire  work  in  Chemistry. 


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AN  INITIAL  FINE  OF  25  CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  SO  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $I.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


TLU  AU     reoa 

IAIU  0  S  rum 

%/nlV  "  o  LNI  LJ 

uui  3  0  1994 

RECEIVED 

OCT  2  ^  iqq4 

—  •*•  •    *     "IvIVT^"11 
—  /^iQ/^l  II  —  j1  "1  |<    >•  •   r  »  l  '  i^ja 

CIRCULATION  DEP1L 

LD  21-95m-7,'37 

CDH7flbDDSl 


545(199 


0964 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


